Improving the angular color uniformity and the lumen output for multi-chip white LED lamps by green Ce0.67Tb0.33MgAl11O19:Ce,Tb phosphor

In this paper, we propose and discuss how to enhance the color uniformity and the lumen output of multi-chip white LED lamps (MCW-LEDs). This can be done by combining the green Ce_0.67Tb_0.33MgAl₁₁O₁₉:Ce,Tb phosphor (CeTb) and phosphor compounding. We find that the proposed method can have a significant effect on MCW-LEDs performance. Through simulation results, it is confirmed that the color uniformity and the lumen output of MCW-LEDs with average correlated color temperatures of 7000 and 8500 K grow with the concentration of CeTb, while the color rendering ability decreases. With proper choice of CeTb concentration, good performance of MCW-LEDs can be obtained.